Atomically resolved imaging of highly ordered alternating fluorinated graphene.

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Producing ordered two-dimensional (2D) chemical derivatives of graphene is crucial for fabricating high-quality monolayer devices.
• Graphene derivatives with controlled functionalization are essential for advancing electronic and material applications.

Purpose of the Study:

• To investigate the structural order and stability of C2F chair, a novel graphene derivative.
• To determine the feasibility of using C2F chair in monolayer device fabrication.
• To establish methods for distinguishing between different graphene-fluorine phases.

Main Methods:

• Obtained focal series of images of graphene and C2F chair using an aberration-corrected transmission electron microscope at 80 kV.
• Utilized focal series exit wave reconstruction (EWR) to analyze the atomic structure of C2F chair.
• Employed electron diffraction to assess the long-range order and distinguish between different fluorinated graphene phases.

Main Results:

• C2F chair was identified as a stable graphene derivative exhibiting pristine long-range order within functionalized domains.
• EWR images revealed strict alternation of carbon and carbon-fluorine pairs in C2F chair over domain sizes of at least 150 nm².
• Electron diffraction confirmed ordered domains of C2F chair to be ≥ 0.16 μm², with functionalization occurring on one side only.

Conclusions:

• C2F chair demonstrates significant long-range order, making it a promising candidate for monolayer device fabrication.
• The study validates theoretical predictions regarding the one-sided functionalization of ordered C2F chair domains.
• Electron diffraction serves as an effective technique for differentiating between graphene, C2F chair, and CF₂ 2D phases.